Applications of vibro-acoustic measurement and analysis in conjunction with tribological parameters to assess surface fatigue wear developed in the roller-bearing system

2021 ◽  
pp. 135065012098246
Author(s):  
Shashikant Pandey ◽  
Muniyappa Amarnath
Keyword(s):  
Roller Bearing ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Stribeck Curve ◽  
Fatigue Wear ◽  
Surface Fatigue ◽  
Rolling Element ◽  
Measurement And Analysis ◽  
Contact Surfaces ◽  
Bearing System

Rolling-element bearings are the most commonly used components in all rotating machinery. The variations in the operating conditions such as an increase in the number of operating cycles, load, speed, service temperature, and lubricant degradation result in the development of various defects such as pitting, spalling, scuffing, scoring, etc. The defects that appeared on rolling contact surfaces cause surface deterioration and change in the vibration and sound levels of the bearing system. The present experimental investigations are aimed at assessing the surface fatigue wear that appears on the contact surfaces of roller bearings. The studies considered the estimation of specific film thickness, analysis of surface fatigue wear developed on the rolling-element surfaces, surface roughness analysis, grease degradation analysis using Fourier transform infrared radiation, and vibration and sound signal measurement and analysis. The results obtained from the experimental investigation provide a good correlation between surface wear, vibration, and sound signals with a transition in the lubrication regimes in the Stribeck curve.

scholarly journals Experimental Investigations to Analyze Surface Contact Fatigue Wear by Using a Dynamic Response of the Roller Bearing System

2021 ◽  
Author(s):  
Shashikant Pandey ◽  
Amarnath Muniyappa
Keyword(s):  
Surface Defects ◽  
Roller Bearing ◽  
Contact Fatigue ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Fatigue Wear ◽  
Lubrication Regimes ◽  
Promising Tool ◽  
Bearing Contact ◽  
Contact Surfaces

Abstract Bearings are used to reduce friction between two rolling /sliding members of the machines. Under normal operating conditions, an increase in the fatigue load cycles on the bearing contact surfaces results in surface defects viz. micro pitting, macro pitting, spalling and scuffing, thereby causing lubricant degradation. Hence, to maintain a better operating performance of rotating machines, it is essential to keep track of operating parameters. This paper describes the results of experimental investigations carried out to assess wear propagation on bearing contact surfaces using tribological and vibration parameters. Results obtained from experimental investigations provide a good correlation between the increase in surface fatigue wear and corresponding effects on transition in lubrication regimes, increased vibration levels, variations in rheological properties of lubricant and wear mechanisms developed on the contact surfaces of the roller bearing. The proposed approach can be used as a promising tool to assess incipient faults developed in roller bearing.

A Multiphase Computational Study of Oil-Air Flow Within the Bearing Sector of Aeroengines

2015 ◽  
Author(s):  
Akinola A. Adeniyi ◽  
Hervé P. Morvan ◽  
Kathy A. Simmons
Keyword(s):  
Boundary Conditions ◽  
Computational Study ◽  
Roller Bearing ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Contact Friction ◽  
Outer Race ◽  
Roller Bearings ◽  
Rolling Elements ◽  
Inner Race

The bearing chamber of an aeroengine houses roller bearings and other structural parts. The spatial limitation, high operational speeds of the HP shaft and the proximity to the combustion chamber can make the operating conditions of the bearing chamber challenging. A roller bearing consists of an inner race, an outer race and a cage constraining a number of rolling elements. In the aeroengine application, oil is introduced into the bearing chamber via the inner race regions of the bearing into the rolling elements interstices. This provides lubrication for the roller bearings. The source of heat in the bearing chamber is mainly from rolling contact friction and the high temperature of combustion. Cooling results from the oil transport within the bearing chamber and thus an efficient transport of oil is critical to maintaining the integrity of the entire structure. The bearing chamber contains the oil which is eventually scavenged and recycled for recirculation. Experiments have been conducted over the years on bearing chamber flows but often simplified to create the best emulation of the real aeroengine. The complexity of the bearing chamber structure is also challenging for experimental measurements of the oil characteristic in the roller bearing elements and the bearing chamber compartment. Previous experiments have shown that the oil continuum breaks up in the bearing chamber compartment but it is not quantitatively clear how and what parameters affect these. Previous simulation attempt of bearing chamber, also, have been limited by the boundary conditions for the oil. This work presents a computational fluid dynamics (CFD) transient simulation of flow in the bearing sector in an attempt create boundary conditions for such models. The current results show that the oil emerges in the form of droplets into the bearing chamber compartment with speed of the order of 10% of the shaft rotation.

Inclination of Principal Residual Stress and the Direction of Cracking in Contact-Fatigued Ball Bearing Steel

1979 ◽  
Vol 23 ◽  
pp. 341-348
Author(s):  
Kikuo Maeda ◽  
Noriyuki Tsushima ◽  
Masatoshi Tokuda ◽  
Hiroshi Muro
Keyword(s):  
Residual Stress ◽  
Ball Bearing ◽  
Roller Bearing ◽  
High Hardness ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Lubricating Oil ◽  
Peeling Test ◽  
Surface Fatigue ◽  
Ball Bearing Steel

Peeling is a surface fatigue failure of a roller bearing that consists of many shallow pits less than 10 pm in depth and cracks that link the pits. Peeling occurs rather easily on a smooth Surface when in contact with a rough surface under insufficient thickness of the lubricating oil film.X-ray residual stress measurements on and under the contact surface after a peeling test revealed that the 2θ versus sin2ψ curve is not linear and that it curves depending upon the rolling contact condition and especially upon the existence of slip. Nonlinearity of the 2θ-sin2ψ) curve has been reported by Wakabayashi in a study of residual stress accompanying the grinding of soft steel and by Faninger in a study of residual stress due to rolling contact with annealed steel, but hot in the case of high hardness steel such as ball bearing steel. No complete explanation of this non-linearity has been made as yet.

Influence of Solid Contaminants on the Fatigue Life of Lubricated Machine Elements

2006 ◽  
Vol 220 (5) ◽  
pp. 441-445 ◽  
Author(s):  
F Ville ◽  
S Coulon ◽  
A. A. Lubrecht
Keyword(s):  
Surface Defect ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Damage ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Damage Initiation ◽  
Process Creation ◽  
Rolling Element ◽  
Machine Elements

Solid contamination of lubricants is one of the main causes of premature rolling contact fatigue of machine elements (e.g. rolling element bearings in automotive gearboxes). Understanding the indentation process (creation of surface defect by debris passing through the contact) and the surface damage initiation allows the prediction of the induced risk. This article summarizes the work of the authors and proposes a risk prediction on the basis of operating conditions and dent geometry.

A New Rolling Contact Surface and “No Run-In” Performance Bearings

1995 ◽  
Vol 117 (1) ◽  
pp. 166-170 ◽  
Author(s):  
Rao S. Zhou ◽  
Fukuo Hashimoto
Keyword(s):  
Plastic Deformation ◽  
Rolling Contact ◽  
Rolling Element Bearing ◽  
Test Results ◽  
Deformation Properties ◽  
Rolling Element ◽  
Rolling Elements ◽  
Element Bearing ◽  
Contact Surfaces ◽  
Running Torque

Plasticity indexes are usually used to describe the elastic-plastic deformation properties of a rough surface. The contact surfaces of any new rolling element bearing always change during the bearing run-in period until arriving upon a relatively stable surface texture. In this paper, a new random isotropic surface with very low plasticity index is proposed and created for the surfaces of rolling elements bearings. From both the calculated surface parameters and the run-in torque test results, the special rolling contact surfaces demonstrated “No Run-In” characteristics. Lower running torque is obtained from bearing tests and longer fatigue life is also expected by the subsurface stress analysis.

Understanding white etching cracks in rolling element bearings: State of art and multiple driver transposition on a twin-disc machine

2016 ◽  
Vol 231 (2) ◽  
pp. 203-220 ◽  
Author(s):  
Arnaud Ruellan ◽  
Jérôme Cavoret ◽  
Fabrice Ville ◽  
Xavier Kleber ◽  
Bernard Liatard
Keyword(s):  
Failure Mode ◽  
Electrical Potential ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Lubricant Additives ◽  
Formation Mechanisms ◽  
Rolling Element Bearings ◽  
Local Criterion ◽  
White Etching Cracks ◽  
Rolling Element

Among the prevalent tribological failures affecting rolling element bearings, an unconventional rolling contact fatigue mode has been identified as white etching cracks. Those correspond to three-dimensional branching crack networks partially bordered by white etching microstructure, eventually leading to premature and unpredictable failure. Recent work supports that this failure mode may be associated with various combinations of operating conditions depending on the application or test rig, but that all seem to converge towards similar tribological drivers related to surface-affected hydrogen evolution at asperity scales, which is known to embrittle the bearing steel. Nevertheless, as white etching cracks remain delicate to reproduce without artificial hydrogen charging, the underlying formation mechanisms remain unsettled. The present work aims to better understand how some of the main tribomechanical and tribochemical drivers may trigger white etching cracks and premature failures. In this study drivers such as sliding kinematics, water contamination, and electrical potential and lubricant additives are progressively transposed on a twin-disc machine that provides an enhanced control of contact parameters. Various attempts advocate that the tested drivers are not self-sufficient to reproduce the failure mode in such apparatus, but confirm that specific lubricant additives may reduce the fatigue life by promoting surface-initiated embrittled cracking similar to white etching cracks. A local criterion accounting for the local sliding frictional power dissipation and the lubrication regime is further proposed to assess the risk of white etching cracks based on the analysis of various reproduction and occurrences.

Investigation on the drag effect of a rolling element confined in the cavity of a cylindrical roller bearing

2021 ◽  
pp. 135065012110260
Author(s):  
Wenjun Gao ◽  
Shuo Zhang ◽  
Xiaohang Li ◽  
Zhenxia Liu
Keyword(s):  
Open Space ◽  
Roller Bearing ◽  
Flow Characteristics ◽  
Experimental Tests ◽  
Windward Side ◽  
Leeward Side ◽  
Drag Effect ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

In cylindrical roller bearings, the drag effect may be induced by the rolling element translating in a fluid environment of the bearing cavity. In this article, the computational fluid dynamics method and experimental tests are employed to analyse its flow characteristics and pressure distribution. The results indicate that the pressure difference between the windward side and the leeward side of the cylinder is raised in view of it blocking the flow field. Four whirl vortexes are formed in four outlets of two wedge-shaped areas between the front part of the cylindrical surface and adjacent walls for the cylinder of L/ D = 1.5 at Re = 4.5 × 103. Vortex shedding is found in the direction of cylinder axis at Re = 4.5 × 104. The relationship between drag coefficient and Reynolds number is illustrated, obviously higher than that of the two-dimensional cylinder in open space.

Dynamics of Rolling-Element Bearings—Part I: Cylindrical Roller Bearing Analysis

1979 ◽  
Vol 101 (3) ◽  
pp. 293-302 ◽  
Author(s):  
P. K. Gupta
Keyword(s):  
Differential Equations ◽  
Normal Force ◽  
Equations Of Motion ◽  
Roller Bearing ◽  
Rolling Element Bearings ◽  
Analytical Formulation ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Bearing Analysis

An analytical formulation for the roller motion in a cylindrical roller bearing is presented in terms of the classical differential equations of motion. Roller-race interaction is analyzed in detail and the resulting normal force and moment vectors are determined. Elastohydrodynamic traction models are considered in determining the roller-race tractive forces and moments. Formulation for the roller end and race flange interaction during skewing of the roller is also considered. Roller-cage interactions are assumed to be either hydrodynamic or fully metallic. Simple relationships are used to determine the churning and drag losses.

scholarly journals Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

2018 ◽  
Vol 21 (8) ◽  
pp. 1286-1297 ◽  
Author(s):  
Antonio Gil ◽  
Andrés Omar Tiseira ◽  
Luis Miguel García-Cuevas ◽  
Tatiana Rodríguez Usaquén ◽  
Guillaume Mijotte
Keyword(s):  
Heat Transfer ◽  
Coke Formation ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Thermal Design ◽  
Working Fluid ◽  
Transfer Model ◽  
Lumped Model ◽  
Bearing System

Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine-operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieved due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available fall outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This article presents a fast three-dimensional heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine-operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads to oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures. Model validation is illustrated, and finally, the main results are discussed.

The Influence of Lubricant Supply Conditions and Bearing Configuration on the Performance of (Semi) Floating Ring Bearing Systems for Turbochargers

2017 ◽  
Author(s):  
Luis San Andrés ◽  
Feng Yu ◽  
Kostandin Gjika
Keyword(s):  
Heat Flow ◽  
Thermal Energy ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Engine Oil ◽  
Large Temperature ◽  
Oil Viscosity ◽  
Supply Pressure ◽  
The Impact ◽  
Bearing System

Engine oil lubricated (semi) floating ring bearing (S)FRB systems in passenger vehicle turbochargers (TC) operate at temperatures well above ambient and must withstand large temperature gradients that can lead to severe thermo-mechanical induced stresses. Physical modeling of the thermal energy flow paths and an effective thermal management strategy are paramount to determine safe operating conditions ensuring the TC component mechanical integrity and the robustness of its bearing system. On occasion, the selection of one particular bearing parameter to improve a certain performance characteristic could be detrimental to other performance characteristics of a TC system. The paper details a thermohydrodynamic model to predict the hydrodynamic pressure and temperature fields and the distribution of thermal energy flows in the bearing system. The impact of the lubricant supply conditions (pressure and temperature), bearing film clearances, oil supply grooves on the ring ID surface are quantified. Lubricating a (S)FRB with either a low oil temperature or a high supply pressure increases (shear induced) heat flow. A lube high supply pressure or a large clearance allow for more flow through the inner film working towards drawing more heat flow from the hot journal, yet raises the shear drag power as the oil viscosity remains high. Nonetheless, the peak temperature of the inner film is not influenced much by the changes on the way the oil is supplied into the film as the thermal energy displaced from the hot shaft into the film is overwhelming. Adding axial grooves on the inner side of the (S)FRB improves its dynamic stability, albeit increasing the drawn oil flow as well as the drag power and heat flow from the shaft. The predictive model allows to identify a compromise between different parameters of groove designs thus enabling a bearing system with a low power consumption.

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